While our copy of zlib is missing upstream commit 263b1a05b04e ("Allow
deflatePrime() to insert bits in the middle of a stream.") we do have
Z_FIXED support, and so the majority of the code changes in 5c44459c3b28
("Fix a bug that can crash deflate on some input when using Z_FIXED.")
apply here directly and cleanly. As this has been assigned a CVE, lets
go and apply these changes.
Link: 5c44459c3b
Reported-by: "Gan, Yau Wai" <yau.wai.gan@intel.com>
Signed-off-by: Tom Rini <trini@konsulko.com>